ACTH (Adrenocorticotropic hormone)

Chemical Pathology

ACTH (adrenocorticotropic hormone) is secreted by the anterior pituitary in response to corticotrophin-releasing hormone from the hypothalamus as well as in response to stress.
ACTH stimulates secretion of steroids including Cortisol from the adrenal cortex. This peptide hormone undergoes diurnal variation and samples are usually collected in the morning (08:00 - 10:00).
ACTH is used in the investigation of Cushing's syndrome, and in differentiating primary from secondary causes of adrenal insufficiency.
An isolated ACTH level is rarely diagnostically useful, levels should be interpreted in the context of the concurrent cortisol concentration.

For adults, blood taken into a 4mL EDTA tube sent immediately to the laboratory on ICE with a simultaneous tube for cortisol.

For children, blood taken into a 2mL EDTA tube sent immediately to the laboratory on ICE with a simultaneous tube for cortisol.

For neonates, blood taken into an 1.0mL minicollect EDTA tube sent immediately to the laboratory on ICE with a simultaneous tube for cortisol.

Following collection, samples must be immediately put on ice and delivered to the lab within 10 minutes.

Relevant clinical details, including current medication. Samples and request forms must be labelled with time of collection as well as sample date.

The samples are sent for analysis once a week to King's College Hospital, London. Results are expected back within 3 weeks.

If required more urgently for clinical reasons, please contact the duty biochemist to discuss.

9am: ≤50 ng/L

Midnight: ≤10 ng/L

All results must be interpreted in the context of the current cortisol levels, the time of sample collection and the clinical status of the patient.

To learn more about ACTH visit Lab Tests Online

Page last updated: 17/05/2023